Starting and stopping device for a diesel engine

ABSTRACT

Device for starting and stopping a diesel engine including a valve in the fuel supply conduit for the engine and an electric supply circuit controlled by a main electric switch having &#39;&#39;&#39;&#39;stop,&#39;&#39;&#39;&#39; &#39;&#39;&#39;&#39;accessories,&#39;&#39;&#39;&#39; &#39;&#39;&#39;&#39;garage,&#39;&#39;&#39;&#39; &#39;&#39;&#39;&#39;operation,&#39;&#39;&#39;&#39; and &#39;&#39;&#39;&#39;starting&#39;&#39;&#39;&#39; positions. The valve is shifted between a stable open position and stable closed position by an opening coil and a closing coil respectively of an electromagnetic device. The opening coil is connected between ground and a pair of the electric supply circuit across which voltage is applied when the main switch is on the &#39;&#39;&#39;&#39;starting&#39;&#39;&#39;&#39; contact and the closing coil is connected between the &#39;&#39;&#39;&#39;accessories&#39;&#39;&#39;&#39; contact and ground in series with a normally-closed switch which is opened by a relay whose actuating coil is connected between the &#39;&#39;&#39;&#39;operation&#39;&#39;&#39;&#39; contact and ground.

United States Patent Leger [54] STARTING AND STOPPING DEVICE FOR A DIESEL ENGINE [72] Inventor: Andre Leger, Sartrouville, France [73] Assignees: Automobiles Peugeot, Paris; Regie Nationale Des Usines Renault, Billancourt, France [22] Filed: June3, 1971 [21] Appl.No.: 149,467

[30] Foreign Application Priority Data June 11, 1970 France ..2 i460 [52] US. Cl .290/38, 290/37, 123/179 UNITED STATES PATENTS 3,371,656 5/1968 Stauffer et al "123/ 179 H [4 1 June 6, 1972 3,551,686 12/1970 Koehler ..290/ 38 Primary Examiner-G. R. Simmons Attorney-Bums, Doane, Swecker & Mathis ABSTRACT Device for starting and stopping a diesel engine including a valve in the fuel supply conduit for the engine and an electric supply circuit controlled by a main electric switch having stop," accessories," garage," operation, and starting positions. The valve is shifted between a stable open position and stable closed position by an opening coil and a closing coil respectively of an electromagnetic device. The opening coil is connected between ground and a pair of the electric supply circuit across which voltage is applied when the main switch is on the starting" contact and the closing coil is connected between the accessories" contact and ground in series with a normally-closed switch which is opened by a relay whose actuating coil is connected between the operation contact and ground.

2 Claims, 2 Drawing Figures PATENTEDJUM 6 I972 FIGJ.

FIG.2

STARTING AND STOPPING DEVICE FOR A DIESEL ENGINE The present invention relates to a device for starting and stopping a diesel engine and more particularly to the control of the closing element of the fuel conduit.

It is known that automobile constructors make efforts to construct devices controlling diesel engines which ensure the starting and stopping of the engine by the same operations as for petrol or gasoline engines, notwithstanding the absence of the electric ignition means.

The French Pat. Appln. of Add. No. 69 34340 filed on Oct. 8, 1969, by the Applicants describes such a device in which the heating circuit, the starting circuit and the device actuating the closing element of the fuel conduit, are controlled by a general switch which is identical to those employed in petrol or gasoline engines and operated in the same manner both for stopping and starting the engine. In this prior arrangement, the closing element .of the fuel conduit is incorporated in an electromagnetic device of known type which has two stable positions and in which there is an automatic limitation in the consumption of current during the movement of the moving part. Although this arrangement is technically satisfactory, it is relatively costly owing to the multiplicity of the necessary component parts and in particular to the reversing contacts and relays so that it is hardly suitable for mass-produced vehicles.

An object of the invention is to provide a device which is simpler and substantially cheaper and has satisfactory operational features.

It is applicable where the general switch can assume, as is usual, five successive switch positions namely stop, accessories, garage, operation and starting, which correspond solely, as concerns the electrical function of this general switch, to the following different cases:

Stop all the circuits are switched off.

Accessories certain accessories, such as the radio, can be supplied with power.

Garage all the circuits are switched off.

Operation this is the normal position of engine operation, all the circuits are supplied with power except the heating and starting circuits. 1

Starting in this position, which is an unstable position, the heating circuits and starting circuits are supplied with power but the accessories circuit is switched off.

- According to the invention, the closing element of the fuel conduit is actuated by an electromagnetic device having two stable positions and an actuating coil for each direction of displacement, the opening coil of the closing element being connected between ground and a part of the circuit which carries current when the switch is placed on the starting" contact, the closing coil being connected between the accessories contact and ground in series with an opening switch of a relay whose coil is connected between the operation" contact and ground.

. Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawing.

' In the drawing FIGS. 1 and 2 show two embodiments of the invention.

FIG. 1 shows a general switch 1 of known type whose moving contact element 1 is capable of occupying two positions diagrammatically represented by thearrow 2 (stop), 3 (accessories), 4(garage), 5 (operation) and 6 (starting), the latter position being unstable. This switch has fixed contacts 7, 8 and 9 which are adapted to co-operate with the moving contact 1 and have the following functions. The contact 7 corresponds to the circuit for the accessories, such as the radio, which one must be able to operate even when the engine is stopped. The contact 8 corresponds to the power supply during normal utilization of the vehicle. The contact 9 corresponds to the supply of power to the unit B pertaining to the heating and starting circuits; an example of such a unit is described in detail in the aforementioned French Pat. Appln. of Addition No. 69 34340 so that it is unnecessary to give a complete description thereof here.

When the moving contact 1 is in position 2 or 4, the contacts 7, 8 or 9 are switched off or open. When the switch is in position 3, only the contact 7 is connected to the supply. In position 5, the contacts 7 and 8 are connected to the supply. In position 6, the contacts 8 and 9 are connected to the supply.

The closing element or valve 10, inserted in the fuel conduit 11 and usually incorporated in the pump, is actuated by a moving part 12 which is shifted in the direction for opening the conduit by a coil 13 and in the direction for closing the conduit by a coil 14. The coil 13 is connected between the contact 9 and ground. The coil 14 is connected between the contact 7 and ground. Connected in series with the coil 14 is an opening switch 15 which is actuated by a relay whose coil 16 is connected between the contact 8 and ground M. The independence of the coils 13 and 14 permits a selection of the characteristics of each as a function of the force to be provided for each direction of displacement of the closing element 10. I

The device operates in the following manner The moving contact 1 is brought to position 6 in thus moving, the moving contact passes first to the position 3 which supplies power to the coil 14 since the switch 15 is closed. This has no effect on the closing element which was already closed. When the moving contact 1 reaches position 5, the coil 16 is supplied with power, the switch opens and the coil 14 is no longer supplied. When the moving contact I" reaches the position 6, the coil 13 is supplied with power and this opens the closing element 10. The heating and then the starting of the engine are thus simultaneously achieved.

The switch 1 is then returned to position 5, in which coils 13 and 14 are switched off since switch 15 is maintained open.

To stop the engine, the moving contact 1 is shifted rearwardly. When this contact 1 leaves position 5, the coil 16 is no longer supplied with power, the switch 15 closes and the coil 14 is supplied with power at the moment when the switch moving contact 1 moves to position 3, which causes the closing element 10 to close the fuel conduit 11.

I It can be seen that such an arrangement performs the function defined in the preamble.

However, in this very simple arrangement,the coil 15 carries current when the switch contact I" is in position 3 which results in a relatively large consumption of current.

The modification shown in the diagram of FIG. 2 remedies this drawback. In this modification, the input of the coil 16 is connected through a first diode 17 to the contact 7 and through a second diode 18 to the contact 8.

The operation of the arrangement shown in FIG. 2 is generally the same as that of the embodiment shown in FIG. 1. However, the coil 16 is supplied with power also when the switch 1 is in position 3, which maintains the switch 15 open. The consumption of current in this position is lower than in the first embodiment, since the coil 16 is of much lower power than the coil 14. In the course of operation of the switch 1 for stopping the engine, the switch 15 closes as the switch 1 passes to position 4, which pemiits a pulse to be sent to the coil 14 at the moment when the switch 1 reaches position 3 before the switch 15 is once again opened by supplying power to the coil 16.

The diode 17 stops the return of current to the contacts 7 and 15 when the switch 1 is in position 6 whereas the diode I8 stops the return is in position 3.

By way of modification and as shown in FIG. 2, instead of the input of the coil 13 being directly-connected to the contact 9, it can be connected to any point of the starting circuit to which a voltage is not connected when the switch 1 is in posiof current to the contact 8 when the switch 1 tion 6; such a connection can of course be provided in the embodiment shown'in FIG. 1.

Having now described my invention what I claim and desire to secure by Letters Patent is 1. A device for starting and stopping a diesel engine comprising a fuel supply conduit for the engine, a closing element inserted in the fuel supply conduit and having a stable conduit opening position and a stable conduit closing position, a source of electricity having one terminal grounded, circuit means for connecting said source to vehicle accessories and to a unit for controlling an engine heating circuit and an engine starting circuit, a main switch inserted in said circuit means and having a moving contact movable to an accessories position in which said source supplies electric power to said accessories through an accessory contact, an operation" position in which said source supplies electric power through an operation contact to the engine for normal engine operation, and a starting position in which said source supplies electric power through a starting contact to said engine heating circuit, said main switch and said circuit means being so adapted and arranged that said accessories are supplied with electric power by said source both for said accessories position and said operation position of said moving contact and said accessories are cut off from said source during passage of said moving contact between each of said positions, an electromagnetic device associated with said closing element and comprising an opening coil for shifting said closing element to said conduit opening position and a closing coil for shifting said closing element to said conduit closing position, first means for connecting the opening coil between ground and a part of said circuit means which carries current when said moving contact is in said starting" position, and second means for connecting said closing coil between said accessories contact and ground, said second means comprising a normally-closed switch combined with a switch-opening relay having an actuating coil which is connected between said operation contact and ground.

2. A device as claimed in claim 1, wherein said actuating coil has an input terminal which is connected to said accessories contact through a first diode and connected to said opera tion contact through a second diode. 

1. A device for starting and stopping a diesel engine comprising a fuel supply conduit for the engine, a closing element inserted in the fuel supply conduit and having a stable conduit opening position and a stable conduit closing position, a source of electricity having one terminal grounded, circuit means for connecting said source to vehicle accessories and to a unit for controlling an engine heating circuit and an engine starting circuit, a main switch inserted in said circuit means and having a moving contact movable to an ''''accessories'''' position in which said source supplies electric power to said accessories through an accessory contact, an ''''operation'''' position in which said source supplies electric power through an operation contact to the engine for normal engine operation, and a ''''starting'''' position in which said source supplies electric power through a starting contact to said engine heating circuit, said main switch and said circuit means being so adapted and arranged that said accessories are supplied with electric power by said source both for said ''''accessories'''' position and said ''''operation'''' position of said moving contact and said accessories are cut off from said source during passage of said moving contact between each of said positions, an electromagnetic device associated with said closing element and comprising an opening coil for shifting said closing element to said conduit opening position and a closing coil for shifting said closing element to said conduit closing position, first means for connecting the opening coil between ground and a part of said circuit means which carries current when said moving contact is in said ''''starting'''' position, and second means for connecting said closing coil between said accessories contact and ground, said second means comprising a normally-closed switch combined with a switch-opening relay having an actuating coil which is connected between said operation contact and ground.
 2. A device as claimed in claim 1, wherein said actuating coil has an input terminal which is connected to said accessories contact through a first diode and connected to said operation contact through a second diode. 